The club announced the moves Tuesday.
The 23-year-old Ellis will be entering his fifth season with the club. He's appeared in 27 games across all competitions, scoring the winning goal against Cruz Azul in the Champions League last year. He also assisted on two winning goals in MLS play.
Carrasco has made 60 appearances over four MLS seasons, first with the Seattle Sounders and then with the Houston Dynamo. His rights were acquired by Sporting KC from Houston during this year's MLS SuperDraft.
Carrasco married U.S. women's national team forward Alex Morgan last month. Morgan also plays for the Portland Thorns of the National Women's Soccer League.